Charcot’s Foot – a Form of Diabetic Foot Disease

Diabetics are susceptible to developing neuropathic arthropathy which is called Charcot Foot. It is a condition in which the muscles that support the arch in the feet weaken due to severe nerve damage. It’s a condition that occurs in up to 30 percent of diabetics who have peripheral neuropathy.  If not detected in time, the consequences are foot deformity and foot ulcers due to nerve damage and poor blood circulation.

Understanding Charcot Foot

Charcot’s foot is named after a famous 19th century French physician. Jean-Martin Charcot (1825-1893). He noticed the presence of damaged and swollen foot joints in some individuals. The abnormality was not the joint swelling itself but the unusual loss of pain and sensation associated with this type of deformity. Charcot described the loss of sensation and discovered the cause to be the result a loss of function in the nerves. Today, the disease bears his name. It is also known formally as neuropathic arthropathy.[1]

Neuropathic arthropathy is described as a painless swelling of the joints that typically occurs in the ankle or foot. This disease is progressive and destructive. Basically it is a disorganization of tissue and nerves that involves the pain fibers so nerve damage is significant.[2] The bones can become weakened resulting in fractures. With continued walking on the damaged foot, alterations to the actual shape of the foot can take place. Most often, this type of foot is said to have a “rocker bottom.”

What causes it?

At the root of Charcot’s foot lies neuropathy. This is a lack of sensation in the feet which is why someone continues to walk on a damaged foot. There may not be total nerve, but it is enough to remove most of the feeling of pain. With the loss or reduction of deep pain sensation comes impairment in the normal sensory mechanisms of protection. This removes the normal reaction of withdrawal whenever excess stress is placed on the joints and bones. In turn, this places the foot at risk from repeated microtrauma originating from external forces e.g. bumping the feet, stubbing the toes. Over time, the joints dislocate and the bones degenerate.[3]

A complication of Charcot’s foot can even occur following the procedure to correct this foot condition. Osteopenia, a weakening of bones and a precursor to osteoporosis, sometimes results after wrapping of the entire leg and foot to prevent load bearing which is a standard procedure for Charot’s foot. Osteopenia makes surgery on the foot difficult. Recent research has indicated the involvement of certain regulators in bone metabolism in the pathogenesis of osteopenia. The involvement of regulators substances plays a central role and may provide a means of discovering better treatment strategies in the future.[4]

Symptoms and Issues

The condition presents the following symptoms to the doctor and patient with diabetes.[5]

  • A swollen mid-foot
  • The foot or feet may be reddened
  • The foot or feet may be warm to the touch
  • Inability to put your shoes on

The situation can be suspected based on clinical exam and is confirmed following an X-ray. This reveals the collapse of the arch of the mid-foot, dislocation of the bones disintegrated into the concavity of the arch and perhaps also some damaged bone. It is incredible such damage is not detectable to the patients before x-rays, but that’s due to the fact the nerves are damaged.

There may be possible wounds to indicate Charcot foot exists despite the nerve damage. The lack of sensation results in increasing the risk of the individual causing harm to the foot. There is no pain – or it is diminished – so a bump to the foot goes unnoticed. A wound can appear. The chance of infection is increased due to the diminished blood supply to the area. Once infected, instead of throbbing and getting attention, the wound is not painful so remains untouched and untreated until infection is in an advanced stage.

The lack of sensation in the foot sometimes causes a person to walk awkwardly. This leads to a pressure ulcer on the foot. Once again, since there is poor blood circulation and high blood glucose, the ulcer often does not heal properly and becomes infected.

Treatment

Treatment may be delayed as a result of misdiagnosis. This is often common during the initial phase of the disease.[6] This hampers the ability to treat the problem while still in its early stages. Charcot foot is addressed in its early stages with stabilization of the bone anatomy. In the acute stage, this involves total casting resulting in complete immobility of the leg and foot. The individual is not able to place any weight upon the foot to prevent further bone damage.

Unfortunately, in this situation the non-weight bearing leg or foot cast has several disadvantages. One of the major problems is osteopenia – a form of bone loss. Furthermore, the unhampered foot may suffer from doing the work of two feet. The osteopenia will make surgery for correcting the problem difficult. However, drugs as pamidronate and alendronate can be used to treat the osteopenia.

If the foot condition becomes chronic, it will be necessary to perform surgery nonetheless. It may include lengthening the Achilles tendon to help restore the foot back to its normal structure. Whatever form of surgery is required, it is better to do it sooner rather than later. If the problem progresses unchecked, the risk for infection becomes high. If infection occurs and is not addressed, the end result may be amputation.

Amputation is an extreme form of treatment and only done when necessary to save a patient’s life. The best results occur when the Charcot’s foot is discovered and treated in a timely fashion. Amputation resulting from undiagnosed Charcot’s foot need not happen if preventive measures are taken.

Prevention

If you have diabetes, you need to take care of your feet. You need to be aware of the potential issues that can affect them. It is important you regularly inspect your feet when you have diabetes and have then examined by your doctor or podiatrist at least once per year. You should talk to your doctor about the risk of developing neuropathic arthropathy. Educate yourself on the signs and their significance. In doing so, you will be able to avoid Charcot’s foot and the ensuing problems.

Overall, it is essential that your program to manage diabetes include the following:

  • Careful monitoring
  • Regular review of your extremities including the feet
  • Early referral of diabetic patients whenever a mid-foot injury is noticed

References 

[1] American Diabetes Association (ADA) (2009). Type 2 Diabetes. Your Healthy Living Guide. Alexandria, VA: ADA.

[2] Marcovitch, H (2006). Black’s Medical Dictionary 41st edition. Lantham, Maryland: Scarecrow Press.

[3] Bishop, FS; Dailey, AT; and Schmidt, MH (2010). “Massive Charcot Spinal Disease Deformity in a Patient Presenting with Increasing Abdominal Girth and Discomfort.” Neurosurg Focus 28 (3):1-3.

[4] Molines, L ; Darmon, P; and Raccah, D (2010). “Charcot’s Foot: Newest Findings on its Pathophysiology, Diagnosis and Treatment.” Diabetes & Metabolism, 36 (4): 251-255.

[5] ADA (2009), op. cit.

[6] Molines et al (2010), op. cit.

[7] This article was originally published July 12, 2012 and last revision and update of it was 9/10/2015.